[reportlab-users] Error using ImageAndFlowables

[Robin Becker]

Hi Lele,

thanks for the report. Unfortunately I have been ill last couple of weeks so have not had time to look at this.

I don't think you are abusing ImageAndFlowables.

List objects were introduced after ImageAndFlowables and I suspect the problem is in the list splitting not working properly for 
this case.

I will take a look as time permits.
-- 
Robin Becker


On 30/04/2018 23:06, Lele Gaifax wrote:
> Hi all,
> 
> one of my apps builds a PDF with a slightly dynamic layout. One part uses an
> ImageAndFlowables, where the size of the image as well as the flowables are
> controlled by the end user.
> 
> At some point it started to crash with a "strange" traceback, and I spent a
> few hours trying to understand the reason, until I found it and distilled the
> little script I'm attaching below.
> 
> The problem happens when the flowables include a List *and* the image is big
> enough to "include" the List (sorry, I find it difficult to explain better
> than that): in other words, if the image is "little" so that on its right
> there are only Paragraphs it works, but as soon its height is enough to
> "reach" the List, it breaks.
> 
> The following script demonstrates the issue: it builds two documents, one with
> a tiny image, the second with a slightly bigger one, that gives this
> traceback (slightly edited to reduce overly long lines):
> 
>      $ python test_image.py
>      Created sample1.pdf
>      Traceback (most recent call last):
>        File "test_image.py", line 39, in <module>
>          doc.build([ImageAndFlowables(Image('pythonpowered.gif', 30, 30), elts, imageSide='left')])
>        File ".../python3.6/site-packages/reportlab/platypus/doctemplate.py", line 1213, in build
>          BaseDocTemplate.build(self,flowables, canvasmaker=canvasmaker)
>        File ".../python3.6/site-packages/reportlab/platypus/doctemplate.py", line 969, in build
>          self.handle_flowable(flowables)
>        File ".../python3.6/site-packages/reportlab/platypus/doctemplate.py", line 834, in handle_flowable
>          if frame.add(f, canv, trySplit=self.allowSplitting):
>        File ".../python3.6/site-packages/reportlab/platypus/frames.py", line 167, in _add
>          w, h = flowable.wrap(aW, h)
>        File ".../python3.6/site-packages/reportlab/platypus/flowables.py", line 1244, in wrap
>          W,H0,self._C0,self._C1 = self._findSplit(canv,iW,aH)
>        File ".../python3.6/site-packages/reportlab/platypus/flowables.py", line 1336, in _findSplit
>          S = cdeepcopy(f).splitOn(canv,availWidth,aH)
>        File ".../python3.6/site-packages/reportlab/platypus/flowables.py", line 881, in cdeepcopy
>          return deepcopy(obj)
>        File "/usr/lib/python3.6/copy.py", line 180, in deepcopy
>          y = _reconstruct(x, memo, *rv)
>        File "/usr/lib/python3.6/copy.py", line 280, in _reconstruct
>          state = deepcopy(state, memo)
>        File "/usr/lib/python3.6/copy.py", line 150, in deepcopy
>          y = copier(x, memo)
>        File "/usr/lib/python3.6/copy.py", line 240, in _deepcopy_dict
>          y[deepcopy(key, memo)] = deepcopy(value, memo)
>        File "/usr/lib/python3.6/copy.py", line 150, in deepcopy
>          y = copier(x, memo)
>        File "/usr/lib/python3.6/copy.py", line 215, in _deepcopy_list
>          append(deepcopy(a, memo))
>        File "/usr/lib/python3.6/copy.py", line 180, in deepcopy
>          y = _reconstruct(x, memo, *rv)
>        File "/usr/lib/python3.6/copy.py", line 281, in _reconstruct
>          if hasattr(y, '__setstate__'):
>        File ".../python3.6/site-packages/reportlab/platypus/flowables.py", line 1561, in __getattr__
>          return getattr(self._flowable,a)
>        File ".../python3.6/site-packages/reportlab/platypus/flowables.py", line 1557, in __getattr__
>          return self.__dict__[a]
>      KeyError: '_flowable'
> 
> This is the sample script:
> 
>      from reportlab.lib.pagesizes import A4
>      from reportlab.platypus import ListFlowable, ListItem, Paragraph
>      from reportlab.platypus import ImageAndFlowables, SimpleDocTemplate, Image
>      from reportlab.lib.styles import getSampleStyleSheet
> 
>      styles = getSampleStyleSheet()
> 
>      doc = SimpleDocTemplate("sample1.pdf", pagesize=A4,
>                              rightMargin=72, leftMargin=72,
>                              topMargin=72, bottomMargin=18)
> 
>      elts = [Paragraph("a adfj kjh kj hkjh k", styles['Normal']),
>              Paragraph("a adfj kjh kj hkjh k", styles['Normal']),
>              ListFlowable([
>                  ListItem(Paragraph("a", styles['Normal'])),
>                  ListItem(Paragraph("b", styles['Normal'])),
>                  ListItem(Paragraph("c", styles['Normal'])),
>                  ListItem(Paragraph("d", styles['Normal'])),
>                  ListItem(Paragraph("e", styles['Normal'])),
>              ], style=styles['ul'])]
> 
>      doc.build([ImageAndFlowables(Image('pythonpowered.gif', 20, 20), elts, imageSide='left')])
>      print("Created sample1.pdf")
> 
>      doc = SimpleDocTemplate("sample2.pdf", pagesize=A4,
>                              rightMargin=72, leftMargin=72,
>                              topMargin=72, bottomMargin=18)
> 
>      elts = [Paragraph("a adfj kjh kj hkjh k", styles['Normal']),
>              Paragraph("a adfj kjh kj hkjh k", styles['Normal']),
>              ListFlowable([
>                  ListItem(Paragraph("a", styles['Normal'])),
>                  ListItem(Paragraph("b", styles['Normal'])),
>                  ListItem(Paragraph("c", styles['Normal'])),
>                  ListItem(Paragraph("d", styles['Normal'])),
>                  ListItem(Paragraph("e", styles['Normal'])),
>              ], style=styles['ul'])]
> 
>      doc.build([ImageAndFlowables(Image('pythonpowered.gif', 30, 30), elts, imageSide='left')])
>      print("Created sample2.pdf")
> 
> Am I abusing the ImageAndFlowables here?
> 
> Thanks in advance for any hint,
> ciao, lele.
>